Motorized dolls have been a favorite toy of children for many years. Conventional motorized dolls include internal motors and control circuits which can move limbs of the doll or make noises in response to impetus from a child. In order to make the dolls more life-like, doll manufacturers have enabled some dolls to crawl across a support surface. As robotic controls became more sophisticated, doll manufacturers then enabled other dolls to walk across a support surface. However, the conventional walking dolls suffer from various drawbacks.
In order to create a realistic walking motion, the internal motors and gears of a motorized doll would have to be very complex to simulate all the nuances of the human body as it takes a step. Not only would the feet and legs need to be controlled precisely, the upper body would also have to be controlled to prevent the doll from tipping over or moving robotically. The complexity of such systems would increase the cost of these conventional walking dolls significantly, which would make the resulting dolls impractical to sell. Thus, doll manufacturers have simplified the internal motors and control circuits to control cost. The dolls are limited to moving in an unnatural manner with these simplified internal components, and these conventional dolls are also generally limited to standing and walking operations.
In a similar fashion, other conventional dolls have been developed which can sit down and stand back up. One example of such a doll is disclosed in U.S. Pat. No. 4,312,150 to Terzian. Again, these dolls suffer from a number of problems. The doll disclosed in Terzian requires 150 degree rotation of each leg to move between the various positions, but this amount of rotation is unnatural for a human leg. The legs of conventional sitting and standing dolls are generally limited to a very specific geometry in order to allow the motorized doll to move between the two positions. The geometry of these legs and the internal components of these conventional motorized dolls make it impractical for the dolls to have any other function other than standing up and sitting down.
The target market for many of these motorized dolls is infants and toddlers just learning how to walk. Thus, a motorized doll that can convincingly simulate the movements of an infant or toddler learning how to walk is desirable. Consequently, it would be advantageous to develop a motorized doll that can perform multiple functions in a realistic manner without requiring extensive and complicated internal components.